Paper can body



April 25, 1939. A. G. HATCH PAPER CAN BODY Filed Nov. 7, 1936 Patented Apr. 25,1- 1939 UNITED STATES PAPER CAN BODY Alexander G. Hatch, Rochester, N. Y., assigner to Fibre Can DevelopmentCorporation, Rutland, Vt., a corporation of Vermont Application November 7. 1936, Serial No. 109,625

9 Claims.

'It has been heretofore proposed to make a paper can body .by preparing a-blank of different uniform widths and rolling said blank upon a mandrel into tubular or cylindrical form with the narrower portion of the blank in contact with the mandrel so as to form a shoulder within the tubular member in spacedv relation to the ends thereof, upon which shoulder` the ends of-the can may seat and be held. -In such can bodies, to provide a shoulder of adequate width the paper stock from which the can body is formed must be relatively thick where a single convolution or thickness is relied upon to provide the shoulder; and Where the stock is relatively thin a plurality of convolutions or thicknesses must be rolled in order to provide a supporting shoulder of sucient width. Practice and experience has determined that the widthof the supporting shoulder must be at least 0.03 of an inch wide. Hence, where paper stock of say 0.01 of an inch thickness is employed it has been heretofore customary and necessary to have at least three overlying convolutions or thicknesses to provide a satisfactory shoulder.

lilly presentzinvention contemplates the provision of canr end supporting shoulders vof desired width with the use of considerably less paper stock than vis now deemed-to be necessary. The preferred manner in whichI propose to accomplish this is by doubling back upon itself the marginal portion of all or a part of the paper stock which heretofore has beenised to provide the shoulder portion of proper width. In other` words, where heretofore two overlying convolutions of paper were necessary to provide a suitable shoulder, I nowuse a s ingle convolution, the

marginal portions of which are doubled back In 'an analogous upon the body of the paper.

manner, where the paper stock is very thin, the

o marginal. portions of one or more of the con-y volutions may be doubled back to provide addi'- tional thickness at the shoulders. 'I'he invention will be better understood from the detailed description which follows when considered in conjunction with the appended drawing wherein I have shown several embodiments of my invention and wherein:

Figure 1 is a diametrical section through a paper can body showing one embodiment of my invention;

Figs. 2, 3 and 4 are fractional diametrical sections through paper can bodies showing modiflcations of my invention;

Fig'. 5 is a fractional plan view of a blank for forming a can body such as shown in Fig. 4;

l of the outer convolution I2,` so as to terminate (Cl. 22S-5.5)

Fig. 6 is a fractional plan view of a blank for forming a can body such as shown, in Fig. 2.

Fig.' 7 is a fractional plan view 0f a blank for forming a can body such as shownrin Fig. 3

Referring to the drawing, the various can body 5 sections disclosed therein are of the type formed by rolling a paper blank upona cylindrical'or other polygonally-shaped mandrel to provide a tubular casing having an'internal shoulder at at least one end and preferably at both ends, against 0 which shoulder or shoulders the ends of the can may seat and be secured. The paper stockv from which these can bodies are made is preferably rst treated to render it impervious to the substance Which the can is yintended to hold, or in 15 other words, treated to render it water-proof if the canV is intended to hold liquid contents dissolved in water, or treated to render it oil or grease proof if the can is intended to hold lubricating oil, grease or the like. 20

In Fig. l the` can body is shown as being oil tubular form and containing three overlying convolutions or thicknesses of paper, the inner two, I0 and II, of` Which are of aheight less than that in spaced relation to ends of the outer convolution I2 to provide internal shoulders I3 and I4 against which a can end such as at I5, is adapted to seat and be held by a beaded over end of the outer convolution I2,.as indicated at I6. To increase the width of the shoulders I3 and I4 without employing any 4additional paper stock than has heretofore been used in the -making of a can of this type, I double back upon itself the marginalportion of at least one of the inner convolutions I0 or II, so as to provide an additional ,thickness of material I3', I4'.' The height oil these doubled back portions I3' and I4 may be the same as the distance that the shoulders I3 and I4 extend inwardly from the top and bottom of the convolution I2 respectively, so that said doubled back portions may be cut directly from the blank from which the outer convolution I2 is formed without increasing the width of the material used therefor. A blank suitable for this 45 purpose is shown in Fig. '7, and has a maximum uniform width Il equalto the height of the can body and a minor uniform width I8 corresponding to the height of the inner convolutions of the can body which yprovide the shoulders. The 50 length of the portion I1 of greater4 width is equal to at least that required to provide one convolution of a can body of r @quired diameter while the portion of lesser width I8 as herein shown is equal to at least 4twice the length required to 55 provide a can of proper diameter; or in other words, the portion of Width IB is suiiicient toe4 provide overlying convolutions or thicknesses for such can body. A part of this portion vi8 of lesser Width, is of a length I9 to provide one convolution of the can body, and is formed with an initial width equal to the normal width I1 of the blank, with its marginal portions I8 of` a width equal to the length of the can body above the shoulder doubled back upon the portion I9 to provide marginal portions of double thickness. The can body shown in Fig. 1 is formed from the blank shown in Fig. 7 by rolling the narrow end of the blank upon a cylindrical mandrel with the doubled back portions in contact `with the mandrel. Of course, the doubled back portions, as well as the body ofthe blank, will be adhesively secured to the body of the blank which it overies.

The can body shown in Fig. 3 is analogous to v that shown in Fig. 1, and primarily differs therefrom in that the folded back lportion I3" in the formation of the can body is disposed outwardly of the mandrel so that in the winding of the can body the ldoubled back portions I8 will be disposed toward the outer convolutions of the ca'n body.

The can body shown in Fig. 2 is also analogous to that shown in Fig. 3 and primarily differs therefrom in that instead of the can body being formed with two convolutions of lesser width, it has but a single convolution I of lesser width. Such can body can be suitably `rolled from a blank such as shown in Fig. 6, which consists of a portion of greater uniform width and a portion of lesser uniform width 2|, each being of a length substantially equal to the circumference of the can body to be formed therefrom. The portion of lesser width 2|, it will be noted, has its marginal portions of double thickness at 2| formed by doubling back upon the body a width of material equal to the distance between the marginal edges of the portion of lesser width and the edges of the portion of greater width.

In the embodiment of the invention shown in Fig. 4', the can body has the general form of that shown in Figs. 1 and 3 and primarily diiers therefrom in that the intermediate convolution Il of the can body is the one provided with a folded back'marginal portion Il' to provide the shoulder ofV increased width adjacent the top of the can body. This embodimentof the invention may conveniently be formed fromv a. blank such as shown in Fig. 5, which consists of a portion of uniform width 22 and portions. and 24 of lesser but uniform width, the portion 23 being intermediate the portions 22 and 24 and being formed with doubled back marginal portions 23 of a character and width quite similar to those heretofore described with respect to portions I8 and 2P. In rolling the blank of Fig. 5 upon a mandrel the top face of the portion 24 as viewed in the drawing is brought into contacting relation with the mandrel and the portion 23 is caused to overlie the portion 24,v so that the doubled back portions 23"will engage the back of the portion 24. .y

Where thel paper stock from which the can` of the outer shell to provide a shoulder within body is tol be formed has a thickness of say about 0.01 of an inch, at least three such thicknesses are required to provide .a suitable can end supporting shoulder. It will ,be seen, however, from the foregoing description that such three thicknesses at the shoulder portion of the can body can be provided from but a double arcane? thickness of the can body proper. Where theV thickness of this paper stock is say-0.015 of an 'inch thick, a single inner convolution of the can body with doubled back marginal portions will provide a shoulder portion of 0.03 of an inch thickness. Where the paper stock is very thin, say about 0.004 orl 0.005 of an inch thick, a greater number of convolutions will be required, but one or more of these may have its marginal portions doubled back and thus reduce by one or more the total number of convolutions required. Where the paper stock is relatively thick and may give rise Ato slight buckling at the doubled back marginal portions during the rolling of the blank, the doubled back portions maybe formed with notches 25 spaced longitudinally of said doubled back marginal portions, and of a depth slightly less than the Width of said doubled back portions as shown'in Fig. 5. These notches will facilitate a smooth rolling of the doubled back portion without detracting from the effective vwidth of the resulting shoulders formed thereby.

In the commercial production of can bodies of the type contemplated by thel present invention it will be apparent that the blanks such as shown in Figs. 5, Grand 7 may be cut from paper stock to provide marginal portions which may be doubled back upon the body of the blank in the course of feeding the blank `to the mandrel for rolling the can bodies. I do not herein show any specific mechanism for accomplishing this,

since the present invention is directed to the can body and method of making same and not tothe machine for making'such can bodies.

From, the foregoing detailed description it will be apparent that I have disclosed several forms of paper can bodies with end supporting shoulders of suitable width .and the method of making such can bodies, by.using less paper stock than has been heretofore required in the fabrication of such can bodies, and without materially adding to the operative steps necessary to the fabrication thereof, and while I have shown and described several embodiments of my invention, I do not wish to be limited to the specific forms illustrated, since it will be apparent to those zov ner shell and an outer shell, with the inner shell f in juxtaposition to the outer shell and securedv thereto, said inner shell having at least one of its ends inwardly spaced from the adjacent end said outer shell and saidshoulder being provided. atleast lin part, by a. folded back marginal portion of the blankfrom whichy the inner shell is formed, said folded back portion being'folded outwardly with respect to the inner wall of the can body.

3. A .tubular paper can body formed from a single blank of paper stock wound upon itself to provide a can body having a plurality of convolutions or thicknesses greater than two with at least two of said convolutions terminatingat one end in inwardly spaced relation to the other convolution, 'to provide a shoulder, and said shoulder having an effective widthgreater than the combined thicknesses of the convolutions providing the shoulder by having at-Ieast one of said last mentioned convolutions formed at said shouldered end with its marginal portion bent back upon itself.

4. A tubular paper can body formed from a single blank of paper stock wound upon itself to provide a can body having a plurality of convolutions `or thicknesses greater than two, with at least two of the innermost convolutions terminating at one end in inwardly spaced relation to the other convolution, to provide a shoulder, and at least one of said innermost convolutions being formed at said shouldered end with its marginal portion bent outwardly back upon itself.

5. A blank for a tubular paper can body consisting of a sheet of paper having adjacent longitudinal portions of different uniform widths, each portion being of a length to provide at least one convolution of a tubular can body of given diameter, and the portion of lesser width having its marginal portion for at least part of its length of double thickness formed by folding a portion of the paper of greater width back upon' itself.

6. A blank according to claim 5 wherein the portion of the blank which is bent back upon itself is of a length to provide at least one convolution of the can body.

7. The method of forming a tubular paper blank with adjacent longitudinal portions thereof of different uniform widths, each portion being of a length to provide at least one convolution of a tubular can body of given diameter, the portion of lesser width being formed at least in part by folding back upon that portion of the sheet the part constituting the marginal difference in the width of the two portions and winding said blank on a mandrel.

8. The method of forming a tubular paper can body which comprises forming a sheet paper blank with adjacent longitudinal portions thereof of different uniform'widthsreach portion being of a length to provide at least one convolution of a tubular can body of given diameter, the portion of lesser width being formed at least in part by folding back upon that portion of the sheet the part constituting the marginal difference in the width of the two portions and winding said blank on a mandrel, beginning with the portion of lesser width. l

9. The method of forming a tubular paper can body which comprises forming a sheet paper blank with adjacent longitudinal portions thereof of different uniform widths, each portion being of a length to provide at least one convolution of a tubular can body of given diameter, the portion of lesser width being formed at least in part by notching the edges at spaced distances apart for a portion of the length of the sheet of greater width' and folding said notched part back upon that portion of the sheet to provide at least a. portion of the sheet of lesser width and Winding said blank on a mandrel, beginning with the portion of lesser width.

ALEXANDER G. HATCH.

can body which comprises forming a sheet paper 

